For certain operations, among them the loading of packaged bakery products into shipping baskets or trays, it is advantageous to employ robotic transfer devices for picking up pre-arranged groups of packages from a delivery location and transferring them to a loading station. At the loading station, the robotic device may reorient the package group and deposit the packages in one or more operations in the shipping basket. Each type of product has an optimum loading pattern in the shipping basket, typically with certain of the product items (e.g., loaves of bread) oriented in one direction and others oriented in another direction. Such pattern loading of the shipping baskets is common in the commercial baking for example.
In order to effectively carry out pattern loading operations with robotic devices, the robotic device, together with the gripping means for the product, may have to execute a series of translational and rotational movements at relatively high speed, such that lightweight construction of the gripper is an important priority. In addition, because product packages of different sizes require different numbers of packages to be loaded into a shipping tray, typically with more than one product orientation, a product gripping device must be easily reconfigurable, so that the gripping device may be quickly adapted to the particular product being delivered to the shipping area. In a typical bakery operation, for example, the product type may change relatively frequently not only between different package sizes, but also between different product types (e.g., bread, rolls, etc.)
Pursuant to the present invention, a novel and advantageous form of robotically mounted gripper device is provided which is of very lightweight yet strong construction, ideally suited for the relatively high translational and orientational accelerations imposed upon it during high speed loading operations. Moreover, the construction of the gripping device is such that it may be quickly and easily disassembled and reassembled and/or adjusted, as necessary, to accommodate product groupings of various types.
In accordance with one specific aspect of the invention, a frame structure for the gripper device is formed of conventional rigid plastic tubing, such as commercially available, low cost PVC tubing. The basic frame structure includes a pair of spaced-apart, longitudinally extending tubular frame sections arranged to be mounted on a robotic device or the like. These spaced members form lateral supports for a plurality of cross members, each mounting a plurality of package-engaging suction devices. The cross members advantageously may be formed of rigid PVC tubing or the like, joined at each end by conventional T-shaped fittings. The cross bar portions of the T-shaped fittings are machined through, so that the fittings are slideably received over the lateral supports and can be adjustably positioned thereon and secured by thumbscrews or the like.
Pursuant to the invention, the individual cross members mount a plurality of tubular supports, carrying individual suction devices. The tubular supports are slideably adjustable along the cross members and may be secured in adjusted positions by means such as thumbscrews or the like.
In accordance with another specific aspect of the invention, the gripper assembly as a whole, formed principally of sections of PVC tubing joined by T-shaped and L-shaped fittings, is arranged with selected components permanently joined and others arranged for free assembly and disassembly. Accordingly, as and when necessary, the entire gripper frame structure may be disassembled in a few minutes time and reconfigured with additional or fewer cross members and more or fewer suction devices mounted on the several cross members, all as may be indicated by the particular type and size of product to be handled. When the type or size of product being delivered to the robotic station is changed, the gripping device may be quickly reconfigured to accommodate a new pattern of products and/or a greater or lesser number thereof.
Pursuant to another feature of the invention, the gripping device is provided on its opposite ends with retractable L-shaped flaps confining pivotally secured to the end members of the gripper frame. When the various product items at the delivery station have been engaged by suction devices, the end flaps are closed, causing the package group to be confined across the two ends of the gripper and also underneath. This enables the package group to better withstand the accelerations imposed thereon during the subsequent lifting, translating and rotating movements exerted upon the gripper by the associated robotic device. In this respect, the products may typically be contained in plastic bags which are engaged and gripped in a limited area by a suction device. Physical confinement of the packages during transfer presents or reduces swinging of the packages and thus enables higher rates of acceleration to be utilized.
For a better understanding of the above and other features and advantages of the invention, reference should be made to the following detailed description of a preferred embodiment of the invention and to the accompanying drawings.